Sectional squib.



No. 791,211. PATENTED MAY 80. 1905.v

J. R. POWELL.4

SEGTIONAL SQUIB.

APPLICATION FILED AUG. l1, 1904'.

y f l f/ NITED STATES Patented May 30, 1905.

ATENT FFICE@ SECTI-ONAL SQUIB.

SPECIFICATION forming part of Letters Patent No. 791,211, dated May 30,1905. Application filed August l1, 1904. Serial No. 220,420.

To all whom, it nui/,y concern:

Be it known that I, JOHN R. POWELL, a citizen of the United States,residing at Plymouth, in the county of Luzerne and State of Penn-Sylvania, have invented a new and useful Sectional Squib, of which thefollowing is a speciication.

My present invention relates to a novel squib designed to facilitate thefiring of blasts with grgater certainty than has heretofore been poss1e.

. In mine-blasting a hole several feet in depth 's drilled, and afterthe charge is inserted refuse is tamped around a needle which latterwhen withdrawn leaves a needle-hole leading to the charge, or in someinstances an iron or other non-combustible tube, known as ablasting-barrel,

opening. In either event a tubular conduit leading back to the charge isformed. Ordinarily the charge has been fired by means of a squib 7-aninammable tube a few inches long filled with an explosive and designedwhen ignited to liy back from the outer end of the conduit to the chargefor the purpose of firing the latter. Obviouslysince the squib isdesigned to iy back to the charge it must be loosely received in thefiring tube or conduit. This, however, is not always practicable,because it is customary to fire a number of blasts at or about the sametime, and as the charges'are comparatively heavy, particularly inblasting otf the solid, the concussion produced by one blast issuficient to dislodge the squib from an adjacent hole. Furthermore, aloose squib is apt to be blown out of a hole by the gases escapingtherefrom and will drop out of place in overhead blasting. Under thesevarious conditions the retention of the squib by some positive means isnecessitated, and such means ordinarily consists in inserting a smallwedge in the outer end of the hole to fasten the squib. Thus in usingsquibs under the conditions named diametrically-opposed requisites areencountered, since it is necessary for the squib to fly back to thecharge and equally necessary for the squib to be held positively againstaccidental move- 1s inserted in the drilled.

ment. The result is that the wedge must be inserted with just sufficientforce to prevent the accidental dislodgment of the sq uib withoutpreventing the same from ying back to ignite the charge. It frequentlyhappens, however, even when the wedge is carefully inserted, that thepressure thereof on the squib will either cause the latter to go outbefore it is completely consumed or to be consumed without flying backto the charge. In either event a mislire results. Obviously, therefore,the ordinary squib, While comparatively inexpensive, is not entirelyecient in overhead blasting or where the holes are gaseous or in theneighborhood of other blasts to be previously lired. This ineflciency ofthe squib has come to be recognized, and in many parts of the countryfuses leading all the Way from the outer end of the hole to the chargeare employed notwithstanding the considerable additional expenseinvolved.

The object of my present invention is to produce what may be termed asectional sq uib, combining the advantageous characteristics andeliminating the objectionable features of both the squib and fuse asordinarily constructed.

To the attainment of this object the invention consists in combining afront fuse-section, which may be securely wedged in the hole, and a rearsquibsection, which when ignited from the fuse-section will fly back tofire the charge.

The invention also resides in certain features of construction andarrangement to be hereinafter described, illustrated in the accompanyingdrawings, and succinctly defined in the appended claims.

In said drawings, Figure lis a sectional view illustrating theapplication of my invention. Fig. 2 is a side elevation of the sectionalsquib shown in Fig. l. Fig. 3 is a sectional elevation thereof. Fig. 4is a tranverse section on the line 4 4 of Fig. 3. Fig. 5 is an elevationof the adjacent ends of the sections in juxtaposition. Fig. 6 is anelevation of a modified construction, and Fig. 7 is a similar view ofstill another form. Y

Like characters designate corresponding ll parts in the several views.

1 indicates a wall of coal or other material to be blasted; 2, thevopening drilled therein; 3, the explosive charge at the inner end ofthe opening, and 4 the material tamped in the opening to form theneedle-hole 5. In the outer end of the hole 5 is securely held-as, forinstance, by a wedge G-the front or fuse section 7 of my sectionalsquib, which also includes a rear or squib section 8 so connected to thesection 7 that it (the rear section) will be free to fly back to thecharge when ignited from the front section. v`

I have adopted the above terms-to wit, fuse-section and squib-section-to designate the primary parts of my device for the reason that thefront section performs merely the office of a fuse, since it conveysiire to the rear section, while the latter performs the office of asquib, inasmuch as it flies back bodily after being ignited to fire thecharge. The

front section comprises in its preferred embodiment a piece of fuse 9 ofusual construction embodying a spirally-wound waterproof cover 10,within which is a suitable highlyiniiammable substance wrapped in fiber.Inclosing this fuse 9 is a casing C, of fiexible slow-burningmaterialas, for instance, paper chemically treated to make it burndeadthat is to say, without flame. rIhis casing C is extended beyond thefront end of the fuse and twisted to form a match 11 and is similarlyextended beyond the rear end of the fuse 9 to form a compressible orcollapsible sleeve 12. The sleeve 12 is designed for the reception ofthe front end of the squib-section 8, which is preferably a piece ofsquib composed, as usual, of a combustible tube 13, containing anexplosive substanceas, for instance, powder 14'. After the end of thesquib-section 8 is inserted in the sleeve 12 the latter is twisted orotherwise compressed thereon to unite the sections suliciently tofacilitate their handling, but in a manner to permit the squibsection tofly back to fire the charge notwithi standing the secure retention ofthe front section 7 by the wedge or other instrumentality employed toprevent the accidental dislodgment of the device by concussion,gas-currents, or gravity. In fact, if desired, the sleeve 12 might befastened to the squib-section, because while this would positively pre-1 vent the separation of the sections prematurely the thin inflammablecharacter of the sleeve would insure its being burned away, and thuspermit the squib-section to shoot back for the performance of itsfunction. Preferably, however, the rear or squib section is looselyinserted in the sleeve and is retained merely by the compression thereonof the latter.

In Fig. 6 I have illustrated a modified construction consisting informing the match 11 and sleeve 12 at the outer ends of two separateterminal casings 10 and 10b.

In Fig. 7I have shown another modification, which consists in utilizingan ordinary squib 15 for the front or fuse section, in which case therear section 14 is merely extended into the end of the tube 13. v

It will now be seen that while my device is essentially a squib and isproportionately inexpensive, since it does not extend the entire lengthof the needle-hole, as a fuse necessarily does, it neverthelesspossesses all of the advantages of a fuse, since it is rigidly retainedagainst accidental dislodgment without in anyT way interfering with thefiring of the blast and since its retained front end may be bent down tothe position shown in dotted lines in Fig. 1, as is customary withfuses, to prevent gases issuing from the needle-hole from extinguishingthe match.

It is thought that from the foregoing the construction, mode ofmanipulation` and many advantages of my sectional squib will be clearlycomprehended; but while the illustrated embodiments of my invention arebelieved at this time to be preferable I reserve the right to effectsuch changes, modifications, and variations of the illustratedstructures as may come fairly within the scope of the protectionprayed."

What I claim is- 1. A squib, comprising two separate and distinctsections, one having the form of a fuse provided with a combustiblesleeve secured to and extended from one end thereof and the yothersection having the form'of a squib extended into the sleeve of thefuse-section and adapted upon ignition to fly back independently of thefuse-section to ignite the charge,

and a match carried by and extended from the front end of thefuse-section and having no connection with the squib-section.

2. A sectional squib, comprising a fuse-section adapted to be rigidlysecured at the front end of the blasting-conduit and having a matchsecured to one end and a iiexible sleeve of combustible material securedto and extended beyond the opposite end thereof, and a squibsectionextended into the sleeve and detachably retained by the compression ofthe sleeve thereon.

3. A sectional squib, comprising a fuse-section having a casing ofcomparatively thin, flexible and combustible material wrapped thereonand having its ends extended to form a match at one end of thefuse-section and a collapsible sleeve at the other end thereof, and asquib-section having one end extended into the sleeve and normallyretained by the collapsing of the sleeve thereon, but capable, uponignition, of flying back independently of the fuse-section to ignite thecharge.

4. A squib, comprising two separate and distinct sections, one of saidsections being a IOC piece of ordinary fuse and the other a piece ofordinary squib, the fuse-section having exible, slow-burning1 materialapplied to its exterior to form a match at one end and a sleeve at theother end, Asaid sleeve surrounding one end of the squib-seetion andcollapsed thereon to temporarily retain the same.

In testimony that I claim the foregoing` as my own I have hereto afixedmy signature 1n the presence of two witnesses.

JOHN R. IJOIVELL. Witnesses:

JOHN L. JONES, THOMAS L. EDWARDS.

